Chewing gums of the types typically known in the art contain many ingredients including flavor ingredients. It is often desirable to produce a chewing gum having a high degree of sweetness and flavor. However, one of the limitations of chewing gum is that the sweetness and flavor are rapidly lost during chewing. This is especially true of "fast-release" chewing gums which release their sweetness and flavor compounds rapidly, creating an initial burst of high intensity sweetness and flavor which is initially pleasing to the consumer but which dissipates quickly during chewing.
"Slow-release" chewing gums, on the other hand, release their sweetness and flavor over a longer period of time but do not provide an initial burst of high intensity sweetness and flavor. Thus, the consumer who desires an initial sweetness and flavor impact must sacrifice the enjoyment of long lasting sweetness and flavor. The consumer who desires a chewing gum having a longer lasting sweetness and flavor must forego the enjoyment of an initial sweetness and flavor impact. Chewing gum manufacturers are constantly trying to extend the time in which consumers can enjoy the sweetness and flavor of chewing gum without sacrificing the quality of the initial sweetness and flavor impact.
In order to control the release of the flavoring agents, and thus lengthen the duration of the flavor, various methods and systems for encapsulating flavoring agents in matrices have been developed and are known in the art. U.S. Pat. No. 2,290,120, issued to Thomas, discloses the mixing of particles of chewing gum base with the flavoring agent to provide a substantially homogeneous mixture. U.S. Pat. No. 2,596,852, issued to Heggie, discloses chemically reacting the chewing gum base with molecules of flavor ingredient, wherein the chewing gum base is a vinyl acetate polymer and the flavor molecule contains an ethylenic bond.
U.S. Pat. No. 2,886,446, issued to Kramer, discloses the coacervation of a typically volatile, water immiscible flavoring oil within a body of gelatin. U.S. Pat. No. 3,085,048, issued to Bush, discloses a process for coating dicalcium phosphate with sugar. U.S. Pat. No. 3,795,744, issued to Ogawa et. al., discloses the coating, encapsulation or combination of flavoring agents with high molecular weight compounds including starches, cellulose, proteins, gums, polyvinyl alcohol and polyvinyl esters. U.S. Pat. No. 3,826,847, issued to Ogawa et. al., contains a similar disclosure. U.S. Pat. No. 3,818,107, issued to Yolles, discloses flavoring agent appended to a polymer backbone, releasable upon hydrolysis.
U.S. Pat. No. 3,962,463, issued to Witzel, discloses the encapsulation of flavor ingredients in gelatin waxes, polyethylene and the like followed by the depositing of the encapsulated flavor particles on the surface of the chewing gum. U.S. Pat. No. 4,217,368, issued to Witzel et. al., discloses the controlled release of a (second) sweetener which is dispersed in, enveloped by, trapped in and otherwise protected by the gum base. A first sweetener, which is relatively unprotected, provides an initial burst of flavor. U.S. Pat. No. 4,259,355, issued to Marmo et. al., discloses a hydrolytically releasable flavor oil entrapped in gelatine, dextrin, gum acacia or modified food starch with the aid of a hydroxypropylcellulose solid suspending agent. A hydrophobic unconfined flavor oil provides an initial burst of flavor.
U.S. Pat. No. 4,230,687, issued to Sair et. al., discloses the encapsulation of flavoring agent in a polymeric medium using rigorous and intimate conditions of mechanical shear to mix the flavoring agent with the encapsulating medium. The flavoring agent is gradually released from the encapsulating matrix at a rate dependent upon the rate of hydration of the matrix, which in turn depends upon the particular matrix used. The polymeric matrix may be derived from natural substances such as casein, a gelatin, modified starches, gums and related materials.
U.S. Pat. No. 4,590,075, issued to Wei et. al., discloses a flavor and sweetener delivery system including a flavoring agent and/or sweetener encapsulated in an elastomeric matrix. The elastomeric matrix is substantially hydrophobic and includes elastomer, elastomer solvent, a wax system and an excipient. The excipient, which is present only in small amounts, can include carbohydrate materials (including partially hydrolyzed starch), polyhydric alcohols and mixtures of carbohydrates and polyhydric alcohols.
By slowing the release of the flavoring agent, the encapsulating methods and systems of the prior art typically also reduce the intensity of the encapsulated flavor. Therefore, as discussed above, a separate and unconfined source of flavor is often necessary in order to prevent loss of the desirable initial burst of flavor. The approaches to flavor modification discussed above generally fall short of providing a single flavor ingredient which simultaneously causes flavor of increased intensity and increased duration.